Jackdaws!!!!

We recently had our gas fires checked - the first time for about 4 years.
The picture shows the three bags of Jackdaw-injected debris from the flue. (Sorry, can't get picture to upload, but you can all imagine three bin-bags full of large twigs, I'm sure) This was merely what the engineer could reach from the hearth - a proper sweep later removed the same amount again, including two nests, I'm told. It is a remarkable effort when you consider we have no trees within a hundred yards.
It is funny that while I've occasionally seen Jackdaws investigate the chimney opening, I have never been aware of any nesting activity (noise, food-carrying, droppings, etc).
Less funny was the effect it had on our fire's ventilation, and we are well aware of the potentially serious consequences. Anybody else in this end of the valley, it's well worth checking out, as according to the gas engineer Todmorden is full of such cases.
Despite their worst efforts, I still think they are the most charismatic of urban birds, but I will be installing a mesh over the flue before next season!